New growth seems more light green than usual

Hello, these plants have been growing for around 2 months from seed. They are in organic living soil, no nutrients used. Water PH is around 7. I recently moved them into this room. The temperature stays around 75 during lights on and 67 at lights out, humidity is around 50 to 55 lights on and 55 - 60 lights out. I have a 315 cmh on one plant and a 225 true watt hlg on the one that is turning what seems too light green at the top. The HLG was at 120 watts, but I turned it up to 225 when I put them in this room. I had a fan oscillating but blowing at both plants from only 6 inches away for a day when I moved them. I had the HLG at only about 18 - 24" above the one that's turning light green after I turned it up and the plant started drooping and not looking happy. I think I may have underwatered a bit because I gave it about 1.3 gallons yesterday and it's looking more and more perkier since then. It's in a 7 gallon smart pot.

I moved the HLG up to about 36" in case that was the issue on 6/31 before lights out.

I attached a photo of what it looked like on June 28th, when I moved them and it still looked really good. Anyone have any ideas if the coloring is something to worry about? Could it be from under watering a little or too much light?

The first photo is from June 28th, the rest are today.

I'm on my lil smart phone, looking like Mg def.

Those girls may have consumed what the soiI had to offer, for one or more nutrients. I assume they need nutrients, but I'm a dummy with soil.

TintEastwood said:

I'm on my lil smart phone, looking like Mg def.

Those girls may have consumed what the soiI had to offer, for one or more nutrients. I assume they need nutrients, but I'm a dummy with soil.

Click to expand...

I just transplanted into this 7 gallon from a 1 gallon about 2 weeks ago, so it seems unlikely it's used up all the nutrients in the super soil already I would think. Someone I know said they think it's normal and they will darken in time.

When you see appearance of mag def on the top of the plant its often light stress. Mg is mobile.